Bead Expansion: EPS block molding machines typically start with the
process of bead expansion. The pre-expanded EPS beads, which are soft and pliable, are fed
into the machine.
Pre-Expanding Chamber: The pre-expanded beads are transferred to a
pre-expanding chamber within the machine. In this chamber, the beads are exposed to steam and heat, causing
them to expand further. The steam softens the polystyrene and vaporizes the pentane gas
inside the beads, creating a cellular structure within the
material.
Block Molding: Once the beads have been expanded, they are
transferred to the block molding section of the machine. The expanded beads are placed into a mold or tooling that defines
the shape and size of the EPS foam blocks. The mold consists of multiple sections that can be opened and
closed.
Closing and Pressing: When the expanded beads are in the mold, the
sections of the mold are closed, and pressure is applied to
compress the beads. This compression allows the beads to fuse together, forming a solid
and uniform structure.
Cooling: After the pressing stage, the mold is cooled to solidify
the EPS foam and shape it into a block. Cooling is typically achieved through the circulation of chilled
water or other cooling methods. Proper cooling ensures that the foam retains its shape and
stability.
Mold Opening and Block Ejection: Once the EPS foam block has cooled
and solidified, the mold is opened, and the finished block is
ejected from the machine. The mold sections may have ejector pins or other mechanisms to
facilitate the removal of the molded block.
